I am new to the world of logical volumes. I have installed a Linux (CentOS), and the installer created an 50 GB root logical volume (mounted at /), and a 475 GB home logical volume (mounted under /home). There is also 32 GB swap. The hard disk is a hardware-raid-virtual-disk (I don't know if this is relevant)

Now it turned out that I need a large space under /opt, but most of my free space is under /home. I guess the solution must be to create a new opt volume (the space, 200GB should be taken away from the home volume), and mount it under /opt.

It should be easy, but all the tutorials/questions I found deal with setting up LVM from the ground up (which I don't need)... So what is the command to take away a given space from an existing volume, and give it to a new volume? Thank you in advance.